BitDepth#870 - January 29

Thinking about backup hits home when a drive goes away suddenly. Thoughts about backup systems and strategies.
A salvation of bits
Rod Taylor had a solid grip on his 1960 Time Machine.

After last week’s deliberation on enterprise scale storage and backup, it might be useful to consider how to replicate some of that automated convenience without having a staff of IT professionals hovering over your computer system like mildly irritated angels.
The simple truth is that backup is a giant PITA. It is not fun, it is rarely pleasant and it’s can be a mauling bear to setup and to maintain. But it’s necessary, like regular exercise is necessary, and the consequences of a digital heart attack can be just as debilitating.

At the core of any consideration of any backup strategy should be the clear understanding that any trust that you place in that brand-new system on your desk is woefully misplaced.
It’s hardware, and hardware always fails. It may fail in ten years or in the next ten minutes, but it’s going to fail and that’s a bet on a single point of failure is one that you shouldn’t take.

Whether it’s envy over the technologies that are available in a server appliance like HP’s StorageServ systems or naked fear of losing critical work and cherished digital memories, a good, reliable backup system should be as much a part of your technology arsenal as Angry Birds: Star Wars.

I’ll confess this much as well. While I like to return to backup strategy as a column topic as a matter of principle, in the hope that somebody reading the column avoids the tragedy of losing all their data in a single point of failure collapse, I had my own reminder of the fragility of modern storage quite recently.

A month ago, I decided to move from an iMac to a Mac tower system for my desktop server. This offered an opportunity to upgrade from a single two terabyte drive to a more robust server storage plan.
I promptly stocked the tower with a 240GB SSD for the OS and scratch files with three two terabyte drive in the remaining bays for images, media files and backup respectively.

I had an ornate plan for strategically turning off the incremental backup on that fourth drive occasionally and to set it to save copies of selected folders. I then promptly forgot to turn it off and was rewarded for that forgetfulness just a few days later when the drive with my photographs disappeared. A new drive, just days in the system, gone.
Half an hour later it was all back, restored from the backup drive which had kept an up-to-date copy of all the files courtesy of Apple’s Time Machine.

When I’ve written about this technology previously, I’ve been a bit snobbish about it, preferring to suggest folder level organisation and backup strategies, which I still use for long term archives.
Incremental backup, which Time Machine does so well, should really be part of your digital safety net on any production level computer system (
How Time Machine works).

The standard for backup is called the full backup, which makes a copy of all your existing files on a secondary drive every time it’s activated. This is the safest backup scheme of all, because it keeps a full copy of your data with every backup, but in today’s era of multi-gigabyte projects, it demands insane storage capacities.

Incremental backup looks at your data, references what it’s already backed up and only copies data which has been changed since the last backup. This makes for smaller backup data sets, but the software doing the backup must be able to restore a current folder without confusing multiple versions of files.

Time Machine does this well, and hides its complexity convincingly from its users. Built in solutions on Windows aren’t as elegant, unfortunately. You might begin your exploration of incremental backup with
Cobian, which does incremental, differential and full backups. Many other solutions exist as do resources offering advice.

A folder level, assignment focused system of backup is still the cornerstone of my archival methodology, but when I’m busy making other plans, an automated incremental system kicks in and weaves a data safety net I can forget about.

Related links…
File crash
Chris Laird and I talk Time Machine
Nuke and pave
Cloud storage
Backup drives
File obsolesence
Rescuing data
Backup software
Marlon Griffith’s data loss nightmare
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